Calibration and Mall Security

I’m in Memphis this week for some meeting at Shelby Systems while Donnie attends the basic Shelby training as part of his ramp up at Faith. Last night we picked up a rental car and the Memphis airport. While driving to the hotel I noticed the compass on the dash said CAL. Being a bit of a geek I knew that meant the compass in the car had not been calibrated. The upshot is that means the car is very new and I’m one of the first renters, the downside is that CAL was going to drive me nuts knowing that the car wasn’t doing something I know it could do – namely showing me what direction I’m going. I know my GPS tells me the direction but it’s the principle of the thing.


We checked into the hotel and then ran out to grab a bit to eat. On the way back from eating Donnie suggested I go ahead and calibrate the compass. To calibrate the compass in a GM model car you select calibrate on the dash board menu and then drive in circles for it to calibrate it. I’m not joking, look it up in any GM manual. On the way back to the hotel we found an empty mall parking lot and gave it a go.

So I started driving in circles, slow enough that I didn’t make Donnie sick. First I tried small circles to the left, then larger circles to the left, then small circles to the right, then larger circles to the right and finally I did some figure 8’s. All the while the dash kept reading, “Drive in Circles”.

5 minutes later I finally realized that the zone must not be set. In order for the compass to calibrate you have to know what zone you are in so the compass can calculate the magnetic north based on your longitude and latitude and let you know your direction in reference to the magnetic north. How do I know this? Like I said, I’m a bit of a geek. Because of that inherent geekness I also happened to know that Indiana is in zone 5 and that Memphis, TN is also in zone 5 as it is almost due south of Lafayette, IN. So, I set the compass zone to 5 and started driving in circles again.

By this time mall security had noticed something odd with a car driving round and round and round in their parking lot. I completed my first circle after setting the zone and the dashboard displayed those magic words, “Compass Calibrated” and the letter SE appeared in place of the CAL. Also at this time a mall security vehicle appeared next to ours.

The mall officer rolled down his window and asked what we were doing. I explained we were from out of town and our rental car compass needed calibrating and to do that we had to drive around and circles and that the empty mall parking lot behind our hotel seemed like a reasonable place to perform said calibration. His respond, “I’ve always wondered how you do that.”

He wished us a good evening and said he was glad his boss didn’t notice us and sent us on our way. I’m not sure what that meant but I’m glad our compass is calibrated. I don’t plan charge Enterprise for the services performed.